Patent Application
20130330132
The present invention in general relates to a tension frame for its application with a riser system and in particular to a tension frame, which houses at least two pre-installed pressure control equipments for its application with a riser system for hydrocarbon exploration and production.
Particularly, the present invention relates to a tension frame according to the preamble of claim 1.
In riser systems for hydrocarbon exploration and production, such as in subsea operations from a vessel or exploration and production platform, coiled tubing and wire line operations, are common. These are applied for lowering equipments or measurement devices into the well or for pumping chemicals through the coil and various other operations.
Pressure control equipments are applied in coiled tubing and wire line operations for sealing around a coiled tubing or a wire line, while allowing the wire line or coiled tubing to pass down into the riser.
The riser is kept under proper tension by a tension system. This means that the vessel or platform is moving with the waves while the riser is kept substantially still. Consequently, there may be a substantive relative movement between the riser and the vessel.
A tension frame is deployed on top of the riser and is adapted to follow the movement of the riser. The tension frame is used for wire lining and coiled tubing operations into the riser. An example of a tension frame is shown in US 2005/0126790. US 2006/0196671 and US 2007/0089884 show other examples of a tension frame.
Conventionally, a tension frame is installed between a surface flow tree and a winch in the drilling or intervention tower. During wire line operations, wire line pressure control equipment is hoisted into the tension frame and connected to the top of the surface flow tree.
During coiled tubing operations, the coiled tubing pressure control equipment is lifted into the tension frame and connected to the top of the surface flow tree.
The above operations of lifting the pressure control equipment are time consuming and risky, having regard to the vertical relative motion between the tower and the riser with the tension frame.
Accordingly, there is a long felt need for a technology which ensures increased efficiency and faster as well as less complicated operation in respect of installation of pressure control equipments in tension frame during wire line and coiled tubing operations. There is also a need to avoid installing and de-installing of pressure control equipments up and down to the tension frame, on top of the surface flow tree, during such operations.
The present invention meets the abovementioned long felt need by providing a tension frame which houses at least two pressure control equipments pre-installed and parked in a ready-to-use state, one each for wire line and coiled tubing operations.
It is the prime object of the present invention to provide a tension frame for its application with a riser system in hydrocarbon exploration and production, which ensures increased efficiency and faster and less risky operations in respect of installation and de-installation of pressure control equipment, during wire line and coiled tubing operations.
It is yet another object of the present invention to provide a tension frame for its application with a riser system in hydrocarbon exploration and production, which avoids installing and de-installing of pressure control equipments up and down to the tension frame, on top of the well control unit such as a surface flow tree, during wire line and cabled tubing operations.
It is a further object of the present invention to provide a tension frame which ensures smooth and easy wire line and coiled tubing operations during hydrocarbon exploration and production.
All through the specification including the claims, the words “hydrocarbon”, “riser”, “tension frame”, “riser system”, “pressure control equipment”, “well control unit”, “tower”, “ tree or surface flow tree”, are to be interpreted in the broadest sense of the respective terms and includes all similar items in the field known by other terms, as may be clear to persons skilled in the art. Restriction/limitation, if any, referred to in the specification, is solely by way of example and understanding the present invention.
According to a first aspect of the present invention there is provided a tension frame for its application in a riser system for hydrocarbon exploration and production. The tension frame is installed on a well control unit atop at least one riser in the riser system. According to the invention, the tension frame houses at least two pre-installed pressure control equipment units in ready to use state, one each for coiled tubing and wire line operations for activation of any one of the pressure control equipment units.
According to an advantageous embodiment of the first aspect of the present invention, the wire line pressure control equipment and coiled tubing pressure control equipment are parked inside the tension frame on either side of the riser center, immediately atop the well control unit.
According to another advantageous embodiment of the first aspect of the present invention in the event of activation of the wire line pressure control equipment along the riser centre for connection with the well control unit, the coiled tubing pressure control equipment is arranged to be parked inside the tension frame, on one side of said riser center.
According to a further advantageous embodiment of the first aspect of the present invention, in the event of activation of the coiled tubing pressure control equipment along the riser centre for connection with the well control unit, the wire line pressure control equipment is arranged to be parked inside the tension frame, on one side of said riser center.
Preferably, the tension frame is accessible by a lifting and lowering device for activating and parking the wire line pressure control equipment and the coiled tubing pressure control equipment.
According to a second aspect of the present invention there is provided a riser system for hydrocarbon exploration and production. The riser system comprises at least one riser extending from a well head to a drilling or intervention unit, a well control unit atop the riser and a tension frame installed on the well control unit. According to the invention, the tension frame of the riser system houses at least two pre-installed pressure control equipments in ready-to-use state, one each for coiled tubing and wire line operations, for activation of any one of said pressure control equipments.
Having described the main features of the invention above, a more detailed and non-limiting description of a n exemplary embodiment will be given in the following with reference to the drawings.
The following describes a preferred embodiment of the present invention and some relevant prior art which are purely exemplary for the sake of understanding the invention and non-limiting.
The present invention relates to well control equipment on or near the surface in conjunction with a high-pressure well intervention riser system from a drilling or intervention unit such as a vessel or a rig.
The present invention addresses the placement of pressure control equipment for cable and coiled tubing in a tension frame on a well control unit, such as a tree or a surface flow tree, on top of a high pressure riser.
The invention will be further clear from the figures where like reference numerals represent like features
As shown in
The tension frame 2 carries a well line pressure control equipment unit 3 lined up with the riser centre 10 atop the tree 5.
All these
The tension frame can be accessed by a lifting and lowering device (not shown), which lifts up the wire line pressure control equipment 3 or the coiled tubing pressure control equipment 4 and move it sideways between the parked position in the frame 2 and the center position 10 on top of the tree 5. When one is installed at the center position 10, atop the tree 5, the other is parked on its side and vice versa. This should be clear from
The frame 2 may be a traditional two-dimensional frame with two legs or preferably be a three dimensional frame with four legs. The latter provides a working platform and hence better accessibility to workers.
The tension frame according to the present invention ensures faster and less risky operations and substantially reduces vertical relative motion between the tower and the riser with tension frame, by virtue of its pre-installed pressure control equipments housed within the frame.
For the sake of understanding,
The tension frame 2, of the present invention is equally effective in achieving its objectives when operatively associated with other riser systems, as known to persons skilled in the art. Of course, the tension frame 2, housing two pre-installed pressure control equipments, when installed in the tower 1, is a part of a riser system.
The exemplary figures as described above show two pressure control equipment units for the sake of explanation. It should be understood that the scope of the present invention also intends to embraces more than two pressure control equipments housed within the tension frame, in ready to use state, as this in only limited by the size of the units and the space available within the frame.
The present invention has been described with reference to a preferred embodiment and some drawings for the sake of understanding only and it should be clear to persons skilled in the art that the present invention includes all legitimate modifications within the ambit of what has been described hereinbefore and claimed in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 20120665 | Jun 2012 | NO | national |
